Progress on my attempt at a hidden LA 3-link

I screwed around under my Jeep again this past weekend for WAY TOO LONG and have a tiny bit of progress to show for it. Everything is a compromise between competing issues when trying to build this damn thing! First, I had to clock the t-case a bit to gain some clearance between the front output CV and my 2" thick crossmember mounted with it's bottom flush with the bottom of my sleeved frame rails. The tranny/t-case still needs to be moved up a bit from stock too. I actually raised it as little as possible while still getting some clearance for the front driveshaft. Then I installed the front shaft and let it droop till the cv was in a bind. Hmm, not as much droop as I had thought I would have. Even with this much droop, the shaft got in the way of where the control arm mounts were supposed to go. Things might have worked out better if I could have pushed the crossmember back a bit, but other considerations made that difficult. So, I did a bunch of thinking and planning before finally cutting, grinding, welding and such to come up with what I have. I'm not even sure it will work, but I guess I'm ok with it. The bottom of the Johnnie Joint is 1" below the bottom of the crossmember and with the driveshaft at full droop, I've got less than 1/4" between the top of the Johnnie Joint and the driveshaft. My old crossmember only hung 1.25" below the bottom of the frame, so the bottom of the Johnnie Joint is a tiny bit higher than the old setup while the rest of the crossmember is a bit higher. The arms will be 34.5" to 34.75" long with this crossmember. I still have a bunch of work to do, including the mount for the single long upper link, but at least I actually built something instead of just doing more pondering! Jeff

http://share.shutterfly.com/osi.jsp?i=EeEN2jZq0btmG_

One thing about the URF three link, there's not a lot of extra space!

CRASH

P.S. Especially with a juice box!

are you going to put the single upper between the driveshaft and the tranny, URF style? could the passenger side possibly be easier, or is the starter motor too much in the way?

I know you don't have your MJ with you, so you can't look. The starter is WAY in the way.

CRASH

BrettM said:

are you going to put the single upper between the driveshaft and the tranny, URF style? could the passenger side possibly be easier, or is the starter motor too much in the way?

Click to expand...

BrettM said:

are you going to put the single upper between the driveshaft and the tranny, URF style? could the passenger side possibly be easier, or is the starter motor too much in the way?

Click to expand...

My plan is to mount the single upper ABOVE the CV joint. I plan to make some sort of hoop to go over the CV and then put tabs on the hoop wherever makes the most sense for the upper arm. I MIGHT be able to do a mount like Crash and Jes did keeping it between the CV and the tranny, but I don't think it'll fit. The other end of the upper then may run into problems with the tranny shifter cable, mount, etc. I'll have to cross that bridge when I get to it. First, I've got to come up with some sort of exhaust route to fit it over the crossmember and clear the long lower arm during compression! I like the single long arm above the pumpkin as I think the action of the gears provides most of the tendency for the housing to rotate. The link located there keeps rotation under control as it's source. Braking is the other big factor that wants to rotate the housing. Jeff

Damn, it takes me forever to do anything! After two more LATE nights and one full vacation day, I got the crossmember and modified exhaust bolted in! The truck is driveable once again. http://share.shutterfly.com/osi.jsp?i=EeEN2jZq0btmHI I pieced together about fifty pieces of exhaust tubing (from two Borla header to cat pipes) to make one complicated pipe that clears the passengers side long arm mount, the crossmember, and dumps into the old cat back system in a pretty much stock location. I even added a hanger off the new crossmember close the where the old hanger mounted off the tranny. I reused the old hanger from my '92, but modified both parts. I hope there is enough cushion when the engine flexes yet not too much where the pipe hits obstructions. It clears the crossmember by about 1/2". I did clearance the floor just a bit with a hammer...which proved awful easy...like too easy as the first hit dented the floor a good 1/2"! I'm not sure that was completely necessary, but it did increase the room and isn't noticeable inside with the carpet and all.

As for the crossmember, you may wonder what is going on there with the mounting. Well, I previously sleeved my frame rail with 3x4x.25 U shaped steel and made it bolt on with a number of through the frame sleeves. When I located the crossmember, it overlapped ONE set of through the frame sleeves. So, I tied the mount into this sleeved hole and made a boxed in portion with a through hole to allow a wrench to fit through the crossmember and to the nut on the inside of the frame rail. Pictures show it better than I can describe it. I plan to add four tabs that will be welded to the frame rail sleeves and then put four more bolts through the crossmember mounting plates and through the tabs. I think that will make the crossmember mounting system strong enough to handle the upper and lower control arm mounts. That makes three bolts from the bottom per side into the factory nut strips in the frame rails, one large through the frame bolt per side, and two bolts per side from the bottom through tabs welded to the frame rail sleeves. That's six bolts per side.

I drove it to work this morning and everything worked fine. I even threw it in low range and drove around our field a bit with no issues. So far so good. Jeff

Looks like URF-East is up and running.

When do the LCA mounts get cut off?

That's always a hold-your-stones moment.

CRASH

I'd say you did a lot in that much time. How bout a couple shots with the rattle can so it won't rust up :laugh3: Looks pretty good!

Yeah, a little paint wouldn't hurt. However, it really only puts off the inevitable for a short while around here. Also, I needed to get the damn thing running again so I didn't have time for paint. And finally, I still need to add a mount to the crossmember for the upper control arm as well as the four additional holes and tabs welded to the frame sleeve. And, I wanted to be sure things worked before covering them in paint. Jeff

nice work with the exhaust, looks like a PITA! any concern about the exhaust warming the tranny too much? maybe put a heat-shield in?

I didnt' see any pictures with the arms all hooked up, got any?

BrettM said:

nice work with the exhaust, looks like a PITA! any concern about the exhaust warming the tranny too much? maybe put a heat-shield in?

I didnt' see any pictures with the arms all hooked up, got any?

Click to expand...

The exhaust runs pretty much right next to the tranny cooler lines. I don't really like that, but stock configuration isn't all that much different. I do think it is closer now though. I was thinking that some lines come with a shiny fabric type heat shield on them. Perhaps I could find some of that stuff and wrap the lines? I did rebend the lower tranny cooler hose up some to clear the exhaust as the new pipe location is on top of where the line used to run. As for long arms, I don't even have the material yet! That takes cash. I fabbed everything I've got using one of my short arms with 2.5" Johnny joints pilfered from one side. Oh, a 2x4 is a good estimation of line of site clearance too. This thing is a work in progress you know. Jeff

Jeff 98XJ WI said:

The exhaust runs pretty much right next to the tranny cooler lines. I don't really like that, but stock configuration isn't all that much different. I do think it is closer now though. I was thinking that some lines come with a shiny fabric type heat shield on them. Perhaps I could find some of that stuff and wrap the lines? I did rebend the lower tranny cooler hose up some to clear the exhaust as the new pipe location is on top of where the line used to run. As for long arms, I don't even have the material yet! That takes cash. I fabbed everything I've got using one of my short arms with 2.5" Johnny joints pilfered from one side. Oh, a 2x4 is a good estimation of line of site clearance too. This thing is a work in progress you know. Jeff

Click to expand...

I only see a two-link suspension in those pics......it must really be a hidden three link, eh?

CRASH

CRASH said:

I only see a two-link suspension in those pics......it must really be a hidden three link, eh?

CRASH

Click to expand...

Actually, it's more like a no link in those pictures! Not counting the four short arms and the track bar. Jeff

Some pics for Jeff...



...don't know if those will help, let me know if you need anymore.

Thanks Jes. One of those shots comes pretty close to answering my question. I think a key ingredient to building a long link suspension with the frame end of the links raised above the bottom of the frame rails is the relationship for and aft between the drivers side lower control arm mount and the front driveshaft. One wants the front output as low as possible to keep the fully drooped driveshaft as low as possible for as much droop as possible. However, with the control arm mounted right under the driveshaft, and the desire to mount it as high as possible, it becomes advantageous to locate the control arm end in the crook between the driveshaft and the Double Cardon joint with the driveshaft fully drooped. I didn't realize this when I started this project and ended up locating my crossmember based on how it would fit against my tranny/t-case. If I were to do this again, I would start with the idea that I need to locate the control arm end in the crook between the shaft and the double cardon joint with the driveshaft fully drooped. Then I would raise the front output (via clocking the t-case and/or raising the t-case/tranny combo) just high enough to allow the control arm to sit flush with the bottom of the frame rails. THEN, make the tranny mount wherever it needs to be. I ended up with my control arm mounts a little too far forward. It will work and I'm not going to change it, but these are some tidbits that I've learned along the way. Jeff

Jeff 98XJ WI said:

I screwed around under my Jeep again this past weekend for WAY TOO LONG and have a tiny bit of progress to show for it. Everything is a compromise between competing issues when trying to build this damn thing! First, I had to clock the t-case a bit to gain some clearance between the front output CV and my 2" thick crossmember mounted with it's bottom flush with the bottom of my sleeved frame rails. The tranny/t-case still needs to be moved up a bit from stock too. I actually raised it as little as possible while still getting some clearance for the front driveshaft. Then I installed the front shaft and let it droop till the cv was in a bind. Hmm, not as much droop as I had thought I would have. Even with this much droop, the shaft got in the way of where the control arm mounts were supposed to go. Things might have worked out better if I could have pushed the crossmember back a bit, but other considerations made that difficult. So, I did a bunch of thinking and planning before finally cutting, grinding, welding and such to come up with what I have. I'm not even sure it will work, but I guess I'm ok with it. The bottom of the Johnnie Joint is 1" below the bottom of the crossmember and with the driveshaft at full droop, I've got less than 1/4" between the top of the Johnnie Joint and the driveshaft. My old crossmember only hung 1.25" below the bottom of the frame, so the bottom of the Johnnie Joint is a tiny bit higher than the old setup while the rest of the crossmember is a bit higher. The arms will be 34.5" to 34.75" long with this crossmember. I still have a bunch of work to do, including the mount for the single long upper link, but at least I actually built something instead of just doing more pondering! Jeff

http://share.shutterfly.com/osi.jsp?i=EeEN2jZq0btmG_

Click to expand...

Cool, simultanious 3 link buildups.
Wanna race?

I'm glad Jes got you guys pics. I'm still camera-less.

At least I'm finally worm-free.

CRASH

Jes said:

Some pics for Jeff... let me know if you need anymore.

Click to expand...

Jes, can you post one looking straight back down the UCA from axle to X-member mount?

kid4lyf said:

Jes, can you post one looking straight back down the UCA from axle to X-member mount?

Click to expand...

Does this one help?:

Here's my finished X-member: